I have been using Canadian Tire Formula 1 Synthetic for the past 6 years. Previous to that I had been using Mobil 1 that I purchased from an Esso bulk dealer. From what I know, Esso and Mobil are the same company. This dealer stopped stocking the Mobil 1 and started selling Esso SuperFlo synthetic . It was cheaper and I made the assumption that the SuperFlo was likely Mobil 1 repackaged. Another 2 years passed and I then noticed Canadian Tire Formula 1 (labeled as a 'Full Syntheic') and on the label it stated 'made by Esso'. It was cheaper yet, and I made the assumption that Esso likely wasn't making three qualities of 'synthetic', so it could very well be Mobil 1 also. The Canadian Tire Formula 1 bottle no longer makes any reference to Esso. Does anyone have any information on where the Formula 1 synthetic ranks on the quality scale? Until I read some of the posts on this site, I was unaware that an oil labeled as a 'Full Synthetic' may actually have some dino oil base stock.